The distributor is supplied complete with our heavy duty LT1 Cap, Rotor and the components required for installation. Once installed, you have the ability to adjust the ignition timing – the only distributor that offers timing adjustability! An adjustment screw allows the timing to be tweaked up to +/-5°. The distributor is equipped with a fresh air vent and has an extra thick mounting surface for the cap to eliminate leaks. The pick-up is an advanced optical encoder, a different style of optical pickup than the OEM. This type of pick-up has proven to be very reliable and stable through extreme rpm and conditions. The rotor is bolted to a drive assembly that is indexed to the shaft and is stabilized through the use of a large ball bearing assembly. Leave it to MSD to build an all-out performance distributor to replace the OEM GM LT1 Optispark! We machine an entire billet block of aluminum down into a precise housing that fits in place of the factory piece. Then, we fill it with a reliable new pick-up assembly, a trick timing adjustment mechanism and top it off with an all new MSD distributor cap!